/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.hive.ql.parse;

import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.ql.parse.spark.SparkCompiler;

/**
 * TaskCompilerFactory is a factory class to choose the appropriate
 * TaskCompiler.
 */
public class TaskCompilerFactory {

    private TaskCompilerFactory() {
        // avoid instantiation
    }

    /**
     * Returns the appropriate compiler to translate the operator tree
     * into executable units.
     *
     * set hive.execution.engine = spark
     */
    public static TaskCompiler getCompiler(HiveConf conf, ParseContext parseContext) {
        if(HiveConf.getVar(conf, HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equals("tez")) {
            return new TezCompiler();
        } else if(HiveConf.getVar(conf, HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equals("spark")) {
            return new SparkCompiler();
        } else {
            return new MapReduceCompiler();
        }
    }
}
